Guest Anonymous Posted November 28, 2000 Share Posted November 28, 2000 Anyone ever put a wastegate on a stock manifold? I was thinking about welding a pipe nipple to a flange and just threading it into a tapped hole in the manifold instead of attempting to weld cast iron. Yes? No? ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
Arif Posted November 28, 2000 Share Posted November 28, 2000 I had my pipe and flange done by a professional because of how tricky (not that I could weld anyway) it is to weld the cast iron. My only suggestion is the shorter the pipe the better. If it is too long you risk cracking under extreme conditions. I say that because I showed my welder a picture of James' wastegate mounted and he advised me if I was going to go that long to also weld a bracket from the manifold to the wastegate pipe for added reliability. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 29, 2000 Share Posted November 29, 2000 Well, since I can't weld worth a poop, and I don't even like the idea of welding cast iron, I figured welding up a mild steel flange with a pipe nipple on it would be easy, then screw it into the cast manifold. Any opinions on that? I also have seen a few(very few) spacers that fit the flange between the turbo and manifold, around 4-5cm thick, that have a flange on the side for a wastegate. Just bolt it straight on and plumb the tiny exhaust line. Seems like that would be pretty easy to pop out real quick on a mill, and that's something I can easily do. Anyone used one of these gizmos or know anything about them? ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
TimZ Posted November 29, 2000 Share Posted November 29, 2000 It's preferable to take the wastegate gasses from directly underneath the turbo flange, with the hole for the wastegate inlet centered on the turbine inlet flange. The wastegate would be mounted 'upside down' underneath the turbine housing. This way little or no flow reversal takes place when the wastegate opens. Also, this orientation allows the wastegate outlet to be blended into the exhaust further downstream from the turbine outlet, which is better for flow through both the wastegate and the turbine. Also, this is much easier for packaging and heat management, as the wastegate tubing can be packaged away from the intake manifold and brake master cylinder. I was able to mount an HKS 60mm (not a typo) wastegate in this manner, with no problems (aside from fabbing the wastegate outlet and welding it to the manifold, of course). Unfortunately, I don't have any pictures - sorry... ------------------ Quote Link to comment Share on other sites More sharing options...
TimZ Posted November 29, 2000 Share Posted November 29, 2000 quote: Originally posted by Morgan: (snip) Just bolt it straight on and plumb the tiny exhaust line. How tiny an exhaust line are you talking about here? I would not consider anything less than 1.5" for the wastegate outlet. Quote Link to comment Share on other sites More sharing options...
Drax240z Posted November 29, 2000 Share Posted November 29, 2000 I've seen two different ways, both involve welding the cast manifold. (I'd recommend have a professional weld cast, it can be tricky) James Thagard's manifold: Greg Kring's manifold: Neither of these setups is really ideal, but both are good additions to the stock manifold. To improve on these any more you realy would be better off having a header made. ------------------ "Gimme Fuel, Gimme Fire, Gimme that which I desire" -Metallica Drax240z 1972 240z - L28TURBO transplant on the way! http://members.xoom.com/r_lewis/datsun.html http://members.home.net/drax77/newpage.html Quote Link to comment Share on other sites More sharing options...
clint78z Posted November 29, 2000 Share Posted November 29, 2000 Welcome TimZ good to see you on the board, that is a nice way of mounting the wastegate, I wouldn't have thought it would fit that way . Clearances must have been fairly tight . Preheating is a key factor to welding cast-iron . The high carbon content makes it difficult to get a clean weld . Most average welders will do a crappy job at welding cast-iron . Find a good machine shop !! Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 29, 2000 Share Posted November 29, 2000 And still nobody answers my question about using mild steel pipe threads in a cast iron hole while the whole pile is glowing red hot. ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
jeromio Posted November 29, 2000 Share Posted November 29, 2000 If cast iron is high in carbon, why isn't it called cast steel? By definition, steel is an alloy of iron and carbon. Anyway, several years ago, I welded a cracked up a cast iron manifold for a friend. It was a pain in the ass because it was in three pieces, but the actual welding was pretty easy. I screwed the pieces to a block of wood and got negligible warpage. I'm looking forward to making a tubular manifold whenever I manage to get an L28T. Maybe Simon will share dimension and radius measurements on his..... Quote Link to comment Share on other sites More sharing options...
Andrew Bayley Posted November 29, 2000 Share Posted November 29, 2000 I realize this isn't wastegate related, but I tried screwing some (don't laugh) pipe caps into my exhaust manifoldson my LT1 where the A.I.R. fittings "used" to go. After torquing these fittings on with +100 ft*lbs of torque, they will still loosen themselves up after a week of hard driving. I can't imagine a turbo application being any friendlier. However, if you aren't too concerned with looks, an alternitive would be to use the threaded manifold with pipe idea, then weld a bead where the pipe meets the manifold. This way, the weld strenght would be less critical. TimZ, Where in Dearborn are you located?!?!? -Andy Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 29, 2000 Share Posted November 29, 2000 Well, the wastegate wouldn't be able to turn, so it couldn't work itsself loose... I was worried more with it leaking or siezing hard and not being removable or something like that. Or maybe the manifold cracking around the hole, etc, etc. ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 29, 2000 Share Posted November 29, 2000 Im not familiar with the Turbo manifold, but is there space enough to put a spacer (say 1.5, 2" piece of steel) between the exhaust manifold and turbo and tap that for a wastegate? Hope that doesn't sound to silly, probably put the turbo to far to the left no? Lone Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 29, 2000 Share Posted November 29, 2000 I asked about those things too! Anyone got a s30 with a stock l28t in it? How much room is there to put a spacer between the manifold and the turbo? ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
J Taylor Posted November 29, 2000 Share Posted November 29, 2000 Morgan: Mine has the stock manifold with a deltagate external wastegate. I can get pics of how it's setup the next time I'm under the car. If you want to drive to Birmingham I'm sure turbo specialties can set it up for you. Their number is 205-444-5011. JT ------------------ 1978 280z with 280zx turbo motor. Big turbo, big intercooler, and alotta boost. 8.4 @ 90 1/8 mile with a bad bad traction problem. 1984 300zx turbo....little turbo, no intercooler, and some boost....13.96 @ 98.9 http://turbotaylor.homestead.com/files/index.html Quote Link to comment Share on other sites More sharing options...
TimZ Posted November 30, 2000 Share Posted November 30, 2000 quote: Originally posted by clint78z: Welcome TimZ good to see you on the board, that is a nice way of mounting the wastegate, I wouldn't have thought it would fit that way . Clearances must have been fairly tight . Thanks for the kind welcome... Actually, there is a surprising amount of room under the manifold - the wastegate kind of ends up occupying the space that the stock n/a manifold's collectors would have used. You mainly have to watch out for the steering rod. Like I said - I was able to fit the monster HKS 60mm gate under there - and it fits very well. I'd guess it's about twice the size of the Racegate, and way bigger than the Deltagate. I also was able to route a 2.25" _separate_ exhaust for the wastegate, in addition to the 3" exhaust for the turbine outlet. As far as Morgan's question about the threaded fitting into the manifold - I guess I was tip-toeing around it a bit, but I just can't think of any existing threaded fitting in the manifold that would be anywhere near big enough to accomodate a wastegate. The Deltagate is marginal (BTDT) for anything over 300hp, and it requires 1.5". The RaceGate is bigger still. Do not skimp on wastegate size - you will not be happy with the results. As far as the feasibility of a threaded mild steel fitting - I would say that you'd be hard pressed to get the threads to seal reliably, and it just wouldn't be satisfactory. Once the hot gasses start leaking past the threads the whole joint will most likely rapidly deteriorate. Really - fitting a proper tube and flange and welding it in isn't that hard - I would think that if you were to fit everything up and tack weld it into place, you wouldn't have to pay more than $40 or $50 to have a professional finish the welding for you. I'll try to get a picture of my setup from underneath, if anybody is interested - I have the trans pulled right no for a clutch install, so you can see things a little better than usual. Oh - and Andy - Cherry Hill and Outer, or thereabouts. I work at Ford in Bldg 5. ------------------ Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 30, 2000 Share Posted November 30, 2000 When I say threaded fitting, I mean pipe threads and pipe, like 1-2 inches or so. I don't mean 3/8 inch tubing and flare fittings! I think I'm just gonna go with an internal wastegate for starters and worry about it from there. ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
Oltmann Posted November 30, 2000 Share Posted November 30, 2000 quote: Originally posted by jeromio: If cast iron is high in carbon, why isn't it called cast steel? By definition, steel is an alloy of iron and carbon. You've got it reversed. Steel is actually iron that has been processed to remove some of the carbon. So cast iron is higher carbon (comes out of the ground that way,) it isn't considered an alloy though because carbon is not a metal. Quote Link to comment Share on other sites More sharing options...
clint78z Posted November 30, 2000 Share Posted November 30, 2000 I am not saying that threaded NPT pipe would not seal, but there is a good chance it will fail . On a 2 1/2" pipe has 15/16" thread engagment, with the first 1/4" not providing any sealing at all . Then you get different expansion rates from different metals . The spacer like TimZ suggested looks like a real clean way to go and offers better boost control . It appears there is more room than I thought down there . [This message has been edited by clint78z (edited November 30, 2000).] Quote Link to comment Share on other sites More sharing options...
TimZ Posted December 14, 2000 Share Posted December 14, 2000 Just got back some pics of my wastegate setup on the modified Cartech manifold, in case anyone's interested Thanks, Morgan [This message has been edited by TimZ (edited December 14, 2000).] [This message has been edited by TimZ (edited December 14, 2000).] [This message has been edited by TimZ (edited December 14, 2000).] [This message has been edited by TimZ (edited December 14, 2000).] [This message has been edited by TimZ (edited December 14, 2000).] [This message has been edited by TimZ (edited December 14, 2000).] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 15, 2000 Share Posted December 15, 2000 Go to z31.com/upload and upload your pictures there. The url will be http://z31.com/unsorted/ of course is whatever you name the files before you upload them. Then do the ubb code like it says. ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
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